The present invention relates to a method for selecting an anti-herpes viral compound and a method for selectively inhibiting herpes viruses in a human host in need of such treatment.
The herpesviruses comprise a large family of double stranded DNA viruses. Eight of the herpes viruses, herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and human herpes viruses 6, 7, and 8 (HHV-6, HHV-7, and HHV-8), have been shown to infect humans. Several of these viruses are important human pathogens.
HSV-1 is estimated to affect 100 million people in the U.S. Primary infection of HSV-1 usually occurs between the ages of one and four. Cold sores, the visible symptom, typically appear at a later age, with 20-45% of the population over the age of fifteen affected (Whitley, Clin. Intect. Dis., 26:541-555, 1998).
Genital herpes (HSV-2) is the second most common sexually transmitted disease, with approximately 22% of the U.S population infected with this virus (Fleming 1997).
VZV is the causative agent of chicken pox upon primary infection and can recur in adults as zoster.
EBV results in approximately two million cases of infectious mononucleosis in the U.S. each year. It can also cause lymphomas in immunocompromised patients and has been associated with Burkitt""s lymphoma, nasopharyngeal carcinoma, and Hodgkins disease.
Infection with HCMV often occurs during childhood and is typically asymptomatic except in immunocompriomised patients where it causes significant morbidity and mortality.
HHV-6 is the causitive agent of roseola and may be associated with multiple sclerosis and chronic fatigue syndrome. HHV-7 disease association is unclear, but it may be involved in some cases of roseola. HHV-8 has been associated with Karposi""s sarcoma, body cavity based lymphomas, and multiple myeloma.
These viruses are capable of residing in a latent state within the host. Reactivation of latent virus results from response to environmental stimuli (ex. UV exposure, stress, etc.). Infections or recurrence can be life threatening in immunocompromised patients such as AIDS or transplant patients where HCMV can result in retinitis, pneumonia, and gastrointestinal disease.
The increased immunocompromised population has created an unmet medical need for antivirals against herpesviruses because current therapies do not have a sufficiently broad spectrum against this family of viruses and/or they have limited utility due to toxicity. The present invention provides a method for selectively inhibiting herpesviruses DNA polymerase with compounds that have broad spectrum activity. The method offers a distinct advantage in the treatment of patients in need, particularly immunocompromised patients at risk of infection or reactivation by many members of the herpesvirus family.
The present invention provides a method of selecting compounds that inhibit herpes viruses comprising:
a) measuring IC50 of a compound of interest that inhibits a wild type herpes virus,
b) measuring IC50 of the same compound that inhibits a binding domain mutant herpes virus which is the same strain of the wild type herpes virus,
c) comparing IC50 of step a with IC50 of step b; and
d) selecting the compound of interest wherein the IC50 of step b is at least 3 times greater than the IC50 of step a.
In above method, the order of step a and step b are interchangeable.
The present invention further provides a method of selecting compounds that inhibit herpes viruses comprising:
a) measuring IC50 of a compound of interest that inhibits a wild type HSV-1,
b) measuring IC50 of the same compound that inhibits a binding domain mutant HSV-1 which is the same strain of the wild type herpes virus,
c) comparing IC50 of step a with IC50 of step b; and
d) selecting the compound of interest wherein the IC50 of step b is at least 3 times greater than the IC50 of step a.
In above method, the order of step a and step b are interchangeable.
The present invention further provides a method of selecting compounds that inhibit herpes viruses comprising:
a) measuring IC50 of a compound of interest that inhibits a wild type HSV-2,
b) measuring IC50 of the same compound that inhibits a binding domain mutant HSV-2 which is the same strain of the wild type herpes virus,
c) comparing IC50 of step a with IC50 of step b; and
d) selecting the compound of interest wherein the IC50 of step b is at least 3 times greater than the IC50 of step a.
In above method, the order of step a and step b are interchangeable.
The present invention further provides a method of selecting compounds that inhibit herpes viruses comprising:
a) measuring IC50 of a compound of interest that inhibits a wild type HCMV,
b) measuring IC50 of the same compound that inhibits a binding domain mutant HCMV which is the same strain of the wild type herpes virus,
c) comparing IC50 of step a with IC50 of step b; and
d) selecting the compound of interest wherein the IC50 of step b is at least 3 times greater than the IC50 of step a.
In above method, the order of step a and step b are interchangeable.
The present invention further provides a method for selectively treating diseases caused by herpes viruses in a human host comprising administering a compound to a human in need of such treatment wherein said compound inhibits herpes viruses by interaction with the binding domain in the viral DNA polymerase.
The present invention further provides method for selectively inhibiting herpes viruses in a human host comprising administering a compound to a human in need of such treatment wherein IC50 of the compound that inhibits a binding domain mutant herpes virus is at lease 3 times greater than IC50 of the compound that inhibits a wild type herpes virus which is the same strain as the mutant herpes virus.
The present invention further provides a compound for treating herpesviral infections in a human host wherein IC50 of the compound that inhibits a binding domain mutant herpes virus is at lease 5 times greater than IC50 of the compound that inhibits a wild type herpes virus which is the same strain as the mutant herpes virus.
The present invention further provides a compound for treating herpesviral infections in a human host wherein said compound inhibits the herpesvirus by interacting with the binding domain in the viral DNA polymerase.
The present invention further provides a compound for the inhibiting of herpesvirus DNA polymerases wherein serial passage of a wild type herpes virus in the presence of said compound results in a change of the wild type HSV-1 polymerase at amino acid 823 from valine to alanine.
The present invention further provides a compound for inhibiting herpesvirus DNA polymerases wherein serial passage of a wild type herpes virus in the presence of said compound results a change of the wild type HCMV polymerase at amino acid 823 from valine to alanine and at amino acid 824 from valine to leucine.
The present invention further provides a mutant herpesvirus DNA molecule having a nucleotide sequence selected from a group consisting of SEQ.ID.NO. 1; SEQ.ID.NO. 3; SEQ.ID.NO. 5; SEQ.ID.NO. 7; SEQ.ID.NO. 9; and SEQ.ID.NO. 11.
The present invention further provides a mutant herpesvirus polymerase amino acid molecule having an amino acid sequence selected from a group consisting of SEQ.ID.NO. 2; SEQ.ID.NO. 4; SEQ.ID.NO. 6; SEQ.ID.NO. 8; SEQ.ID.NO. 10 and SEQ.ID.NO. 12.